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Do You Know These 18 Controlled Vocabularies?

Most catalogs use Library of Congress name and subject headings to optimize patron searches. Many libraries use at least a few other controlled vocabularies that relate to areas of emphasis in their collections. And headings from other authority files are likely to find their way into your records from shared sources of catalog metadata.

Backstage’s authority control service currently has options to control headings from 18 authority files. How many of these can be found in your library’s catalog? How many do you actively maintain? And how many have you never even considered?

  • The Library of Congress Names Authority File (NAF) is updated weekly and comprises over 8.2 million entries.
  • The Library of Congress Subjects Authority File (SAF) also has weekly updates and is larger than the NAF, with some 8.6 million entries.
  • The Children’s Subject Authority File (CHILD) is a smaller list, but it also receives weekly attention and now contains more than 12,500 entries. This file is maintained as part of the the Children’s and Young Adults’ Cataloging Program (CYAC) at the Library of Congress.
  • The Medical Subject Headings file (MeSH) from the US National Library of Medicine includes 616,000 entries and is updated on an annual schedule. The library made changes in 2015 to reorganize its data in a faceted structure. If you have older medical headings in your catalog, Backstage can deconstruct that legacy MeSH data to fit the current model.
  • Library and Archives Canada Names (NLC-N) contains 653,000 entries. Since 2018, new English-language name authorities from LAC are added to the LC NAF under a collaboration with LC/NACO through OCLC WorldShare.
  • Library and Archives Canada Subjects (NLC-S) has 659,000 entries which are similarly maintained with a 2019 LC/SACO implementation through OCLC WorldShare.
  • Faceted Application of Subject Terminology (FAST) is a faceted data approach developed by OCLC using LCSH as its source. FAST is updated quarterly and contains over 1.7 million headings.
  • The National Library of Spain file (EMBNE) holds steady at just over 4 million entries.
  • The Queens Library Spanish Language Subject Headings file (QLSP) contains over 11,000 terms.
  • The Art & Architecture Thesaurus (AAT) clocks in at 35,000 headings.
  • The Rare Books and Manuscripts Section Vocabularies holds 1,600 terms.
  • The Thesaurus for Graphic Materials (TGM) offers 7,900 entries.  
  • Guidelines on Subject Access to Individual Works of Fiction, Drama, Etc. (GSAFD) lists 160 entries.
  • The NASA Thesaurus (NASA) includes 18,000 terms.
  • The Education Resources Information Center Thesaurus (ERIC) pulls in 4,500 entries.
  • Homosaurus (HOMOIT) is one of our newest sources, currently comprising 1,600 headings.  
  • Library of Congress Genre Form Terms (LCGFT) comes from a national library source, but we had to put it into one category or the other. (I suppose we could use a see reference.) LCGFT receives weekly attention and comprises 2,000 terms.
  • The OLAC Video Game Genre Terms thesaurus (OLACVGGT) is a database of 66 terms.

Other subject files do contain genre and format terminology, but these two are uniquely dedicated to defining those characteristics.  


Your library’s special collections team may have a file that includes names of locally important people and organizations. Or you may adopt institutionally preferred terminology that doesn’t match politically charged, historically insensitive, or otherwise problematic headings from widely available files.

If you have local headings that should be left untouched by an automated authority matching process, or if you have replacement terms that need to be propagated throughout your catalog, Backstage has ways to help make sure your authority data reflects your library’s priorities.


Does your library use an authority source you don’t see here? Let us know. Several entries in the current list came from clients asking to incorporate additional thesauri to fit their processing needs. We’ll certainly add more sources as new vocabularies are created in the library community and as they’re requested by librarians like you.

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